In the design and fabrication of the structures, material selection plays a critical role. Material selection affects the strength, weight, size, cost, fabrication and assembly of the structural components. Since some materials can be more expensive and harder to complete the fabrication process, the selection of the material used in a structure requires the user to be familiar with fabrication methods for that material.
The main structural materials used are wood and steel. Each of these types of material comes with its own advantages and disadvantages in terms of weight, size, strength properties, cost, and possible fabrication methods.
Wood as a Structural Material
Wood is the most basic structural material. Compared with other materials, wood is very low cost. Another advantage of using wood as a structural material is that it requires minimal tools and fabrication skills. The structures fabricated of wood are relatively lightweight. The size of the structure depends on the durability and amount of strength required in the structure being built. The basic tools that are used to fabricate wooden structures are hand saws and hammers. The wooden structure can be assembled easily by using glue, screws, or nails.
If it is needed to increase the precision and speed of the fabrication process can be used more advanced power tools.
The main disadvantage to using wood for the fabrication of structural components is that compared to steel wood provides a relatively low strength per volume. This makes wood suitable as a structural material only if size is not an issue and there is very little load to bear. For more durable and stronger structures would be necessary to use a relatively large amount of wood in order to achieve similar strength capabilities of steel. Because the size of such a structure using wood would naturally have to be much larger, this is not a reliable material for building durable and strong structures. The user needs to decide if the added structure size out-weights the cost benefits of using wood.
In order to limit damage of wood framed light buildings against lateral forces from high wind and earthquakes, the International Residential Code and the International Building Code recommend several bracing methods including braced wall panels built onsite, shear walls and pre-fabricated shear panels. However, due to the extensive list of components for site-built braces or shear walls, they can be time consuming and difficult to build. There is also a risk of construction delays if contractors do not follow design details closely. Nails that miss framing members, over-driven nails, misplaces hold-downs and over-bent straps, incorrect nail spacing, are mistakes that can delay finalising the building.
Steel is widely used as a structural material. Steel is much heavier than wood and more expensive. A steel structure can cost three to five times more than a similar wood structure. However, the main advantage of steel is the fact that it is much stronger than wood per volume. That allows contractors to use less material in structural components design. Steel structures are more complex and their fabrication process requires heavy duty power tools. To assemble a steel structure also requires more complex tools than a wooden structure. The pieces of the steel structure must be welded together or drilled and assembled with bolts. The advantage to bolting pieces together is that the components can be later disassembled and reassembled fast and easily.
However, when it is necessary to achieve a lighter and more stable structure the welding method of assembling is preferred.
Because steel structures have the potential to rust if used in a humid environment or outdoors they require a protective coat of paint in order to ensure durability.
Engineers often specify steel shear panels as the choice structures for modern buildings. In order to attach finish products these given steel panels may require additional framing. Steel structures can be used for entrance canopies, pergola frames, balustrades, handrails, ladders or steel stairs, industrial metalwork, walkways and platforms and as a more durable replacement for any structures made of wood.
Stainless steel structures are built using the very latest state-of-the art computer assisted technologies such as fastening insertion, metal polishing, laser cutting, and welding. Steel structures can be finished and polished with a variety of surface coatings, depending on the client’s specific requirements.
One of the leading firms specialised in fabricating steel structures is Inner City Steel. You can read more about the various steel structures on the company’s website, at the Web address: http://www.innercitysteel.com.au/